Axle suspension assembly

ABSTRACT

A suspension assembly for tandem axles including an equalizer beam pivot axis defining assembly including (1) a rubber bushed pivot shaft of noncircular configuration and designed to be maintained under compression, rather than being placed under shear stressed, by vertical loading as well as during oscillation of the beam, (2) spring hanger and mounting brackets designed for ease in installation on vehicle frames and axles with maximum strength, (3) substantially stationarily spaced spring bearing surfaces and (4) improved spring-to-axle mounting serving to reduce the length of the static mounted spring midportions.

0 United States Patent i 13,591,197

[72] Inventor Richard L. Haley 3,117,799 1/1964 Behnke 280/1045 2523 N r h Jeff r on Ex n n. New 3,147,963 9/1964 Frazier. H: 280/1045 Castle, Pa. 16105 1,952,128 3/1934 Hahn. 267/52 l2] 1 A 833325 Primary Examiner-Philip Goodman Fled Attome C] A OB d n B J b i Patented July 6, ysarence men an arvey aco son [54] SAUSPENSK')N A'SSEMBLY ABSTRACT: A suspension assembly for tandem axles includs, 23 Draw ng Figs.

, mg an equalizer beam pivot axis defining assembly including U.S. a rubber hushed pivot shaft of noncircular configuration 267/52 and designed to be maintained under compression, rather than [5|] lilt- Cl B608 5/02 being placed under hear tressed, by vertical loading as we Field Of Search .1 280/1045; 5 during oscillation of the beam spring hanger and 267/52 mounting brackets designed for ease in installation on vehicle frames and axles with maximum strength, (3) substantiall sta- [561 Reierences cued tionarily spaced spring bearing surfaces and (4) impr oved UNITED STATES PATENTS spring-to-axle mounting serving to reduce the length of the 3,469,860 9/ 1 969 Hutchens 280/ 1 04.5 static mounted spring midportions.

PATENTEDJUL 6H3?! 3.591.197

SHEET 1 OF 5 Richard L Haley A Homer:

PATENTEDJUL 6I97| 359L197 SHEET 3 OF 5 Richard L Haley IN VIIN'I'UK,

PATENTEDJUL 6|97l 3,591,197

SHEET 5 BF 5 226 22a 7 Fig. 2/

Fig.2.?

Richard L Haley AXLE SUSPENSION ASSEMBLY The axle suspension assembly of the instant invention has been designed to provide a means whereby an efiicient tandem axle assembly may be readily fabricated and mounted beneath a vehicle frame. The suspension assembly utilizes fixed bearing pads of cast steel or other materials in the front and rear hanger brackets to maintain relatively constant spring load centers under both loaded and unloaded conditions and the ride characteristics of the suspension assembly are improved by increasing the available live spring length in both the loaded and unloaded condition. Further, the suspension assembly includes symmetrical cam-type bearing pads in the front and rear hanger brackets that are specifically positioned to gain effective spring length under load conditions.

In addition to the basic components of the suspension as sembly, the suspension assembly utilizes torque arms to position and align the axles whereby the springs of the assembly are not required to be specifically designed for push-and-pull purposes which inherently has an adverse effect on the riding qualities of a tandem axle suspension assembly.

The brackets of the suspension assembly may be cast or prefabricated and are of simple design and the suspension assembly may be readily provided with antihop structure with but a slight addition to the existing basic suspension assembly. Still further, the suspension assembly utilizes a rubber bushed equalizer beam which is basically loaded in compression, both to carry the load and to control articulation thereof. Further, the equalizer beam rubber bushing is constructed and related relative to the beam and its supporting bracket so as to be free of shear forces and to be subject only to compression in both carrying the load and controlling articulation of the equalizer beam.

The main object of this invention is to provide an improved suspension assembly capable of withstanding heavy loads and hard usage with a minimum of wear and maintenance.

Another important object of this invention is to provide the simplification, versatility and reliability of preassembled com- 1 poncnts to reduce the confusion and expense related to producing, ordering, stocking and installing the subject assembly.

Another object of this invention is to provide a suspension assembly for tandem axles that will be capable of maintaining the associated axles properly aligned, rendering an improved smoother ride and also capable of supporting heavy loads during hard usage.

A still further object of this invention is to provide an axle suspension assembly whose equalizer bracket, equalizer beam and front and rear hanger brackets may be readily constructed either by casting or fabrication methods at a reduction in price over existing corresponding components.

A further important object of this invention is to provide a suspension assembly in accordance with the preceding objects and constructed in a manner whereby the front and rear spring bearing pads thereof are operable to maintain relatively constant spring load centers under both loaded and unloaded conditions. Also, a further important object of this invention is to provide torque arm components capable of maintaining the axles properly aligned independently of the associated springs and thereby enabling the springs to be designed fully for ride and rate requirements without having to have incorporated therein design characteristics adapting the springs for pushand-pull purposes.

Another very important object of this invention is to provide a rubber bushed equalizer beam which will be capable of withstanding heavy loads and full articulation without subjecting its rubber bushing to shear forces.

Yet another object of this inveration is to provide an axle suspension assembly including spring seats which may be readily attached to existing axles b; welding in a manner so as to provide maximum length welds between the spring seats and the associated axles.

It is a further object of this invention to provide a suspension assembly in accordance with the preceding objects to provide a suspension assembly including novel means for removably securing the center portions of the associated leaf springs to the spring seats in order to provide maximum live spring lengths and to maintain the nuts of the U-bolts utilized to clamp the spring midportions to the spring seats readily available for service torquing. Another object of this invention is to provide a suspension assembly including spring to-spring seat mounting means in accordance with the immediately preceding object and which will not place undue stresses on the associated axles.

Another important object of this invention is to provide a suspension assembly constructed in a manner whereby movement occurs between both end portions of each leaf spring and the associated spring pads during flexure of the springs so as to divide the wear equally at both ends of each spring and the corresponding wear pads.

A final object of this invention to be specifically enumerated herein is to provide a suspension assembly in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a de ice that will be economically feasible, long lasting and relatively trouble-free in opera tion.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had. to the accompanying drawings forming a part hereof, wherein iike numerals refer to like parts throughout, and in which:

PEG. 1 is a fragmentary side elevational view of a vehicle equipped with the suspension assembly of the instan invention and with portions of the suspension assembly being broken away and illustrated in vertical section;

FIG. 2 is a fragmentary top plan View illustrating the foreground portion of the structure shown in FIG. 1;

FlG. 3 is an enlarged fragmentary transverse vertical sectional view taken substantially upon the plane indicated by the section line 3-3 of FIG. l:

FlG. 4 is a fragmentary longitudinal vertical sectional view taken substantially upon the plane indicated by the section line 4-4 of FlG. 3;

FIG. 5 is an enlarged fragmentary transverse vertical sectional view taken substantially upon the plane indicated by the section line 5-5 of FIG. 1;

FIG. s is a fragmentary longitudinal vertical sectional view taken substantially upon the plane indicated by the section line 66 of PEG. 5,

FIG. 7 is an enlarged fragmentary transverse vertical sec tional view taken substantially upon the plane indicated by the section line 7-7 of HG. 1;

FlG. 8 is a fragmentary longitudinal vertical sectional view taken substantially upon the plane indicated by the section line 84% of PEG. 7;

FIG. 9 is a perspective view of one of the front hanger brackets;

FlG. It) is an exploded perspective view of one of the spring seats and an associated antihop attachment;

FIG. 11 is an exploded perspective view of the equalizer bracket and the equalizer beam;

FIG. 12 is a perspective view of one of the rear hanger brackets;

FIG. 13 is a side elevational view of the assemblage illustrated in FIG. 6 on somewhat of a reduced scale and with the alternate position of the associated torque arm illustrated in phantom lines should it not be desired to use the antihop attachment;

FlG. M is a view similar to FIG. 6 but illustrating a modified form of spring seat having a modified form of antihop attachment secured thereto;

FIG. 15 is a fragmentary transverse vertical sectional view taken substantially upon the plane indicated by the section line 15-15 of FIG E4;

FIG. I6 is a fragmentary horizontal sectional view taken substantially upon the plane indicated by the section line l616ofFIG. 14; v 1 L.

FIG. 17 is a fragmentary enlarged longitudinal vertical sectional view taken substantially upon a plane passing through the center of the upper portion of the modified spring seat illustrated in FIG. 1

FIG. 18 is a perspective view of the modified form; of antihop attachment utilized in'the embodiment illustrated in FIG. 14; I 4 J FIGS. 19 and 20 are fragmentary longitudinal vertical sectional views illustrating the manner in which the spring seat illustrated in FIG. 14 may be modified so as to be adapted for securement to vehicle axles of square and round cross-sectional shapes;

FIG. 21 is a fragmentary top plan view of an axle suspension assembly constructed in accordance with the present invention and illustrating an additional control rod incorporated therein; 3

FIG. 22 is a fragmentary top plan view similar to FIG. 21' but illustrating a second form of control rod being utilized; and

FIG. 23 is a side elevational view of the structure illustrated in FIG. 22.

Referring now more specifically to the drawings, the numeral generally designates a vehicle frame including a pair of opposite side longitudinal rectangular frame members 12 interconnected at their rear ends by means of a transverse frame member 14 extending therebetween.

The tandem axle assembly of the instant invention is generally referred to by the reference numeral I6 and includes a pair of axle members 18 and the suspension assembly of the instant invention which is referred to in general by the reference numeral 20. The components of the suspension assembly are duplicated on opposite sides of the vehicle frame 10 and are substantially identical except for being positioned on a given side of the frame I0 and secured to the'corresponding ends of the axle members 13. Accordingly, only one side of the suspension assembly 20 will be specifically referred to hereinafter.

The suspension assembly 20 includes front and rear hanger brackets 22 and 24, an equalizer beam mounting bracket referred to in general by the reference numeral 26, an equalizer beam referred to in general by the reference numeral '28, identical front and rear springs 30, identical front and rear spring seats referred to in general by the reference numerals 32, antihop attachments referred to in general by the reference numerals 34 and front and rear torque arms generally referred to by the reference numerals 35 and 36.

With attention now invited more specifically to FIGS. 7 and 8 of the drawings, it may be seen that the equalizer bracket member 26 includes a U-shaped channel member 38 which snugly embraces the lower portion of the longitudinal frame member 12 and is secured'thereto in any convenientrnanner such as by welding 430,.bolting, etc. A pair of vertically'elon: gated triangular plates d2 are secured. tothe outer surfaces 'of the opposite sides of thechan'nel member 38191 their upper ends and project downwardly from the channel member-'38.

The lower end portions of the plates 82 are interconnected by means of a rigid sleeve 44 extending I and secured therebetween and the lower terminal ends of the-plates 42 include transversely thickened portions 46 which maybe defined by washers secured to the inner surface portions ofjthe I lower terminal ends of the plates 42.

An elongated rigid member 48 which is generally eggsec'ureditherebetween. Further, corresponding midportions of the plates 56 have a rigid sleeve 62 secured therebetween and opening, at its opposite ends, through the plates 56. The sleeve 62 is generally egg-shaped in cross-sectional shape and the elongated member 48 is loosely received within the sleeve. However, a sleeve 64 of resilient material such as rubber or Neoprene is snugly telescoped over the elongated member 48 and within the sleeve 62. In this manner, the equalizer beam 28 is rubber bushed and any tendency of the beam 28 to oscillate is controlled by compression of the resilient sleeve 64.

With attention now invited more specifically to FIG. 9 of the drawings it may be seen that the front equalizer bracket 22 includes a pair of opposite side plates 62 which are substantially identical except for being right and left handed. The plates 62 are vertically disposed and interconnected by means of an upwardly opening channel member 64, see FIG. 4, secured between their upper ends by welding. The channel member 64 includes a bright portion 66 which defines a longitudinally extending downwardly opening groove 68 and a bearing pad support 70 which is in the form of an elongated bar fastened within the groove 68. The bearing pad support includes a radiused undersurface 72 and the plates 62 are inwardly embossed as at 74 to control lateral spring movement. Further, a rigid tube 76 is secured between the lower ends of the plates 62 and the lower terminal ends of the plates 62 are transversely thickened as at 78. The thickening of the plates 62 as at 78 may also be accomplished by the securement of washers to the inner surfaces of the plates 62.

With attention now invited more specifically to FIG. 12 of the drawings it may be seen that each of the rear hanger brackets 24 includes a pair of substantially identical plates 80 rigidly interconnected at their upper ends by means of a channel member 82 similar to channel member 64. In addition, the rear hanger brackets 24 include bearing pad supports which correspond directly to the bearing pad support 70 and the plates 80 are also inwardly embossed as at 84 and are transversely thickened at their lower ends by the securement of washers 86 to their inner surfaces. The washers 78 and 86 are utilized when the hanger brackets 22 and 24 are fabricated, but may be formed integrally with the hanger brackets if the latter are cast.

With attention now invited more specifically to FIGS. 6 and 10 of the drawings it may be seen that each of the spring seats 32 includes an inverted generally U-shaped channel member 88 defining a pair of upstanding legs 90 interconnected at their upper ends by means of a bight portion 92. The bight portion 92 is centrally apertured as at 94 and a pair of thick straps 96 are welded to the lower ends of the legs 90 and project outwardly therefrom. The straps 96 are slightly upwardly divergent and a pair of bracing plates 98 are secured between the outer marginal edge portions of the straps 96 and outwardly projecting extensions 100 of the bight portion 92. Further, each of the spring seats include partial opposite end walls I02 which are contoured to snuglyembracingly receive shaped in cross-sectional shape is secured between the plates 42 by means of elongated fasteners 50 secured through corresponding bores 52 formed in the plates 42 and corresponding bores 54 formed through the elongated member 48.

The equalizer beam 28 includes a pair of generally parallel plates 56 interconnected at upper opposite end corners by means of transversely extending bearing pads 58 secured therebetween and the lower opposite end comers of the plates 56 are interconnected by means of fasteners 60 rernovably the upper portions of the associated axle member 18.

When the spring seats 32 are secured to the axle members 18', the inner peripheral edge portions of the partial end walls 102 are welded to the axle members 18 and the adjacent inner lower corners of the straps 96 are welded to the axle members 18 throughout their longitudinal extent.

Each of the antihop attachments 34 includes a pair of identical plates 104 which are provided with pairs of aligned apertures i166 and 108 and the plates 104 are interconnected by means of an elongated strap 110 secured between the plates 1M.

I The opposite ends of each strap is apertured as at 11 2 and the opposite ends of the straps 96 are apertured as at 113. Further, each of the spring seats 32 includes a pair of forwardly projecting mounting and gusset plates 1l4 which are suitably apertured as at H 16. Theapertures 112 are registrable with the; apertures 113 formed through the corresponding forward straps .96 and the apertures 108 are registrable with the corresponding apertures 116.

Each of the springs 311 includes three leaf springs 118, 120 and 122 stacked relative to each other withthe spring leaf 118 disposed uppermost and the spring leaf 122 disposed lowermost. The central portions of the springs 118, 120 and 122 may be spaced apart by means of antifriction panel members 124 and the spring leaves 118, 120 and 122 are provided with registered apertures 126 and secured together by means of a fastener 128 secured through the apertures 126.

With attention now invited more specifically to FIGS. 5 and 6 of the drawings, it may be seen that each of the spring seats 32 is utilized to secure the corresponding spring 30 to one of the axle members 18 by means of a pair of U-bolts 132 whose threaded ends are secured through the apertures 116 (and the apertures 112 when the antihop attachments 34 are utilized). The U-bolts 132 embracingly receive the corresponding spring seats 32 therebetween and have their upper bight portions bearing down upon the upper surface 134 of the bight portion 136 of an inverted channel-shaped member 138 including oppositely directed out-tumed flanges 140 which are notched to receive the legs of the U-bolts 132. From FIG. 6 of the drawings it may be seen that the U-bolts 132 are upwardly convergent and that the bolts 142 utilized to secure the free ends of the legs of the U-bolts 132 through the apertures 112 are readily accessible from below for tightening. Further, it may be seen that the head of the inverted fastener 128 is received within the aperture 94 so as to maintain the spring 30 properly located relative to the spring seat 32.

The rear torque arm includes a rubber bushed forward end portion which is secured between the lower terminal ends of the plates 42 of the equalizer bracket by means of a fastener 146. The forward end of the torque arm 36 is received between the washers 46 and the torque arm 36 is adjustable in effective length and has its rear lower end secured between the lower ends of the plates 104 by means of a fastener 148 secured through the lower end of the torque arm 36 and the apertures 1116. Although the straps 110 of the antihop attachments 34 are secured to the forward straps 96 of the corresponding spring seats 32 by means of the corresponding forward U-bolts 132, the upper ends of the plates 1114 of each antihop attachment 34 are secured to the mounting and bracing flanges 114 by means of a fastener 150, see FIG. 1, secured through the apertures 1 08 and 116. However, when the antihop attachments 34 are not used, the lower ends of the torque arms 36 are secured between the flanges 114 by the fastener 150.

With reference now morespecifically to FlGS.14-l7 of the drawings, there may be seen a modified form of spring seat referred to in general by the reference numeral 154. The spring seat 154 includes a generally U-shaped body 156 which is inverted and includes a pair of opposite side plates 158 interconnected at their upper ends by means of a bight portion 160. The lower ends of the plates 158 have downwardly opening recesses 162 formed therein whereby the plates 158 may snugly embracingly receive the corresponding axle member 18 and the marginal edge portions of the plates 158 defining the recesses 162 are welded to the axle 18.

The lower end portions of the plates 158 are interconnected by means of slightly downwardly convergent end plates 164 secured therebetween by welding and the lower ends of the end plates 164 are turned inwardly as at 166 and welded to the corresponding axle member 18. In addition, the spring seats 154 include horizontal bearing plates 168 secured between the corresponding side plates and to the upper marginal edge portions of the corresponding end plates 164. The bearing plates 168 are centrally apertured as at 170 and each forward end plate 164 includes a forwardly projecting mounting boss 170 having a vertical threaded bore (not shown) secured thereto.

An abutment plate 172 is secured between the rear upper marginal edge portions of each pair of opposite side plates 158 and has a smooth bore 174 formed therethrough. In addition, a static wedge member 176 having a vertical locating opening 178 formed thcrethrough is provided and disposed over the uppermost ieaf of the corresponding spring 311 with the upper end of the fastener 128 received in the opening 178 whereby.

horizontal shifting of the static wedge member 176 will be limited. A movable wedge member 1811 is provided and includes a lower rearwardly and upwardly inclined wedge surface 182 which is compatible with the upper forwardly and downwardly inclined wedge surface 184 of the lower stationary wedge member 176. The movable wedge member 1811 has a threaded bore 186 formed therethrough and a bolt 190 has its unthreaded shank portion 192 rotatably received through the bore 174 and its threaded shank portion 194 threadedly engaged in the bore 186. Accordingly, tightening of the bolt 190 will cause rearward movement of the movable wedge member 180 and cause the associated spring 311 to be compressively engaged between the stationary wedge member 176 and the bearing plate 178. Also, it will be noted that the head of the bolt 1911 is provided with a diametric bore 196 whereby the bolt 1941 may be safety wired.

In FIG. 18 of the drawings there may be seen an antihop attachment referred to in general by the reference numeral 198 which is adapted to be utilized in conjunction with the spring seat 1541. The antihop attachment 198 includes a pair of opposite side blades 2111) whose lower end portions have aligned apertures 2112 formed therethrough and whose upper end portions are interconnected by means of a plate 204 secured therebetween and centrally apertured as at 2116. The forward edge of the plate 2114 curves upwardly as at 208 and has a rigid sleeve member 210 secured thereto. When the antihop attachment 198 is utilized, a bolt 212 is secured through the plate 2114 and threadedly engaged in the mounting boss with the rigid sleeve 210 aligned with the bores (corresponding to apertures 116) formed through the mounting plate portions 214 (corresponding to flanges 114) also supported from the spring seat 154. The rear ends of the torque arms 35 and 36 are secured between the lower portions of the plates 2110 by means of fasteners 216 and fasteners 218 are utilized to secure the rigid sleeve portions 210 between the plates 214.

With attention now invited more specifically to FIGS. 19 and 211 of the drawings it may be seen that the lower marginal edge portions of the side plates 158 may have different shaped recesses 220 and 222 formed therein whereby the spring seats 154 may be adapted for securement to axle members 18 and 18" which are rectangular and circular, respectively, in crosssectional shape. Of course, the spring seats 32 may also be similarly modified for securement to axle members of rectangular and circular cross section.

With reference now more specifically to FIG. 21 of the drawings it may be seen that a control arm 226 may be secured between the innermost plate or flange 214 and the innermost plate 42 by means of fasteners 228 and 2311. The control arm 226 is of course to be secured between a corresponding equalizer beam mounting bracket 26 and the corresponding rear spring seat 154 with the control rod 126 paralleling the corresponding torque arm 36. When the control rod 226 is to be utilized, the spring seat 154 is modified by the attachment of a mounting plate 232, see FIG. 23, thereto in order that the fastener 228 may secure the rear end of the control rod 226 to the corresponding rear spring seat 154.

With attention now invited more specifically to FIGS. 22 and 23 of the drawings, there will be seen a modified form of control arm referred to in general by the reference numeral 234 and which is Y-shaped in configuration. The free ends of the arms 236 of the Y-shaped control arm 234 are secured to the opposite side plates 42 of the corresponding equalizer beam mounting bracket 26 by means of fasteners 238 and the corresponding rear spring seat 154 has a pair of mounting flanges or plates 132 secured thereto between which the adjacent end of the control arm or rod 234 is secured by means of a fastener 2411.

In review, it will be noted that the various components of the suspension assembly may be prefabricated (some by casting of fabrication) and readily assembled with a minimum amount of effort. The various hanger brackets 22 and 24, the

spring 30, the torque arms 35. and 36, the equalizer beam mounting bracket 26 and equalizer beam 28 and also the spring seats 32 and antihop attachments 34 may be readily shipped in preassembled form to a point of assembly. Further, the spring seats 32 and 154 are constructed'such that the U- bolts 132 and bolts 190 are readily accessible for periodic torquing. Also, the antihop attachments 34'and 198 are readily attachable to existing spring seats 32 and 154 and the control arms 226 and 234 are also readily attachable to existing spring seats 154 and equalizer beam mounting brackets 26.

The spring bearing pads 58 and bearing pad supports 70 operate to maintain substantially constant distances therebetween during flexure of the springs 30 and the shifting of the opposite ends of the springs 30 relative to the pads 58 and 70 is divided at the opposite ends of the springs 30 so as to equally divide wear on the springs 30 and the various spring pad seats. Also, inasmuch as the U-bolts 132 are upwardly convergent, only extremely short midportions of the springs 30 are maintained against flexure.

lnasmuch as the torque arms 35 and 36 are removably supported at their rear ends, they may be readily disengaged from the antihop attachments 34 and 198 and secured directly to the spring seats 32 and 154, if desired. Also, the spring seats 154 are operative to readily compensate for spring midportions of different heights and each is provided with an abutment fastener 250 which functions to removably retain the corresponding sliding wedge member 180 within the confines of the plates 158. I I

Inasmuch as the elongated member 48, the sleeve 62 and the sleeve 64 are generally egg-shaped in cross-sectional shape, any tendency of the equalizer beam 28 to oscillate relative to the equalizer beam mounting'bracket 26 is resisted by .compression of predetermined portions of the sleeve 64 and the sleeve 64 is not placed under shearing stresses during oscillation of the equalizer beam 28; Also, it will be noted that the larger end of the egg-shaped elongated member 48 is disposed lowermost whereby heavy loading of the vehicle frame is absorbed at the larger end of the elongated member 48.

Only the upper two leaves 118 and 120 of each spring 130 are full length leaves and the adjacent ends of corresponding leaves 120 are turned downwardly as at 250 for abutment with the fasteners 60 in the event the axle members 18 drop excessively away from the longitudinal frame members 12.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those sk'illedin the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable 3. The combination of claim 1 wherein said beam includes a pair of upstanding longitudinally extending opposite side plates, said rigid tube extending between and rigidly secured to and opening through midportions of said side plates, said opposite end portions comprising a pair of opposite end bearing pad plate members secured between pairs of corresponding upper remote end marginal portions of said side plates, said plate members including undersurface portions which are generally planar and slightly upwardly inclined toward their adjacent marginal portions.

4. In combination, a suspension assembly for one side of a tandem axle assembly and for support from the corresponding side longitudinal frame member of an associated vehicle, said suspension assembly including a pair of front and rear hanger brackets and a mounting bracket for mounting on longitudinally spaced portions of said frame member with said mounting bracket spaced between said hanger brackets, an elongated beam supported from said mounting bracket for oscillation about an axis passing transversely through the centerof said beam and disposed at right angles relative to a line connecting said hanger brackets, a pair of aligned leaf spring assemblies, a pair of front and rear spring seats adapted to be secured to corresponding ends of a pair of axle members and clamped to the midportions of said spring assemblies, the I adjacent ends of said spring assemblies being disposed beneath undersurface portions of the opposite ends of said beam and the remote ends of said spring assemblies being disposed beneath undersurface portions of said spring seats,

and a pair of front and rear control arms pivotally connected at their front and rear ends between said front hanger bracket and the front spring seat and the front hanger bracket and between said mounting bracket and said rear spring seat, wherein mounting bracket includes a pair of opposite side laterally spaced panel portions, an elongated rigid body extending between and secured to said panel portions, said body being of noncircular cross section, said' beam including a modifications and equivalents may be resorted to, falling within the scope of the invention.

What I claim as new is as follows: 1. ln combination, an equalizer-beam assembly for a tandem axle assembly, said beam assembly including a mounting bracket for support from a vehicle frame and defining a pair of leaf springs of a tandem axle assembly, said beam including a transverse rigid tube secured thereto whos'e inside cross-sectional shape is complementary to the cross-sectional shape of said body and which is of greater cross-sectional dimensions than said body, said body being loosely received in said tube and a sleeve of resilient compressible and deformable material snugly disposed within said tube and about said body, whereby said beam may oscillate relative to said bracket and tube but its oscillation in either direction from a center position will be yieldingly resisted by compression of predetermined portions of said resilient sleeve. I

2. The combination of claim 1 wherein said body, tube and sleeve are generally egg-shaped in cross-sectional shape with their blunt ends disposed lowermost.

transverse rigid tube secured thereto whose inside cross-sectional shape is complementary to the cross-sectional shape of said body and which is of greater cross-sectional dimensions than said body, said body being loosely received in said tube and a sleeve of resilient compressible and deformable material snugly disposed within said tube and about said body, whereby said beam may oscillate relative to said bracket and tube but its oscillation in either direction from a center position will be yieldingly resisted by compression of predetermined portions of said resilient sleeve.

5. In combination, a suspension assembly for one side of a tandem axle assembly and for support from the corresponding side longitudinal frame member of an associated vehicle, said suspension assembly including a pair of front and rear hanger brackets and a mounting bracket for mounting 'on longitudinally spaced portions of said frame member with said mounting bracket spaced between said hanger brackets, an elongated beam supported from said mounting bracket for oscillation about an axis passing transversely through the center of said beam and disposed at right angles relative to a line connecting said brackets, a pair of aligned leaf spring assemblies, a pair of front and rear spring seats adapted to be secured to corresponding ends of a pair of axle members and clamped to the midportions of said spring assemblies the adjacent ends of said spring assemblies being disposed beneath undersurface portions of the opposite ends of said beam and the remote ends of said spring assemblies being disposed beneath undersurface portions of said spring seats, and a pair of said hanger brackets includes a pair of upstanding opposite side plate elements for se'curement to said frame member, a channeirnernber extending and secured between said portions of said plate elements above and below their lower and upper ends and including upstanding leg flanges interconnected at their lower ends by means of a bight portion extending elements and having an elongated bearing pad defining bar secured in and projecting slightly outwardly of said recess, the undersurface Of said bar being at least slightly radiused transversely of said bar I 

1. In combination, an equalizer beam assembly for a tandem axle assembly, said beam assembly including a mounting bracket for support from a vehicle frame and defining a pair of spaced opposing panel portions, an elongated rigid body extending between and secured to said panel portions, said body being of noncircular cross section, an elongated equalizer beam including opposite end portions adapted to bear downwardly on the front and rear ends of the rear and front leaf springs of a tandem axle assembly, said beam including a transverse rigid tube secured thereto whose inside cross-sectional shape is complementary to the cross-sectional shape of said body and which is of greater cross-sectional dimensions than said body, said body being loosely received in said tube and a sleeve of resilient compressible and deformable material snugly disposed within said tube and about said body, whereby said beam may oscillate relative to said bracket and tube but its oscillation in either direction from a center position will be yieldingly resisted by compression of predetermined portions of said resilient sleeve.
 2. The combination of claim 1 wherein said body, tube and sleeve are generally egg-shaped in cross-sectional shape with their blunt ends disposed lowermost.
 3. The combination of claim 1 wherein said beam includes a pair of upstanding longitudinally extending opposite side plates, said rigid tube extending between and rigidly secured to and opening through midportions of said side plates, said opposite end portions comprising a pair of opposite end bearing pad plate members secured between pairs of corresponding upper remote end marginal portions of said side plates, said plate members including undersurface portions which are generally planar and slightly upwardly inclined toward their adjacent marginal portions.
 4. In combination, a suspension assembly for one side of a tandem axle assembly and for support from the corresponding side longitudinal frame member of an associated vehicle, said suspension assembly including a pair of front and rear hanger brackets and a mounting bracket for mounting on longitudinally spaced portions of said frame member with said mounting bracket spaced between said hanger brackets, an elongated beam supported from said mounting bracket for oscillation about an axis passing transversely through the center of said beam and disposed at right angles relative to a line connecting said hanger brackets, a pair of aligned leaf spring assemblies, a pair of front and rear spring seats adapted to be secured to corresponding ends of a pair of axle members and clamped to the midportions of said spring assemblies, the adjacent ends of said spring assemblies being disposed beneath undersurface portions of the opposite ends of said beam and the remote ends of said spring assemblies being disposed beneath undersurface portions of said spring seats, and a pair of front and rear control arms pivotally connected at their front and rear ends between said front hanger bracket and the front spring seat and the front hanger bracket and between said mounting bracket and said rear spring seat, wherein said mounting bracket includes a pair of opposite side laterally spaced panel portions, an elongated rigid body extending between and securEd to said panel portions, said body being of noncircular cross section, said beam including a transverse rigid tube secured thereto whose inside cross-sectional shape is complementary to the cross-sectional shape of said body and which is of greater cross-sectional dimensions than said body, said body being loosely received in said tube and a sleeve of resilient compressible and deformable material snugly disposed within said tube and about said body, whereby said beam may oscillate relative to said bracket and tube but its oscillation in either direction from a center position will be yieldingly resisted by compression of predetermined portions of said resilient sleeve.
 5. In combination, a suspension assembly for one side of a tandem axle assembly and for support from the corresponding side longitudinal frame member of an associated vehicle, said suspension assembly including a pair of front and rear hanger brackets and a mounting bracket for mounting on longitudinally spaced portions of said frame member with said mounting bracket spaced between said hanger brackets, an elongated beam supported from said mounting bracket for oscillation about an axis passing transversely through the center of said beam and disposed at right angles relative to a line connecting said brackets, a pair of aligned leaf spring assemblies, a pair of front and rear spring seats adapted to be secured to corresponding ends of a pair of axle members and clamped to the midportions of said spring assemblies the adjacent ends of said spring assemblies being disposed beneath undersurface portions of the opposite ends of said beam and the remote ends of said spring assemblies being disposed beneath undersurface portions of said spring seats, and a pair of front and rear control arms pivotally connected at their front and rear ends between said front hanger bracket and the front spring seat and the front hanger bracket and between said mounting bracket and said rear spring seat, wherein each of said hanger brackets includes a pair of upstanding opposite side plate elements for securement to said frame member, a channel member extending and secured between said portions of said plate elements above and below their lower and upper ends and including upstanding leg flanges interconnected at their lower ends by means of a bight portion extending therebetween said bight portion itself defining a downwardly opening channel-shaped recess extending between said plate elements and having an elongated bearing pad defining bar secured in and projecting slightly outwardly of said recess, the undersurface of said bar being at least slightly radiused transversely of said bar. 